Inliners International Forums General Discussion Hi Performance TBI set-ups Mega-Squirt - GM ECM.

Hey, I'd like to here from others that are running TBI on their engines whether its run by MS or GM ECM. I'm about to take the plunge and build up my 250 with the Offy intake and GM ECM. I think it will run very well since 4.3L and 4.1L are very close in C.I.D. Please chine in and give your input.

Thanks in advance.
Randy S. Hager
Venus, TX

Randy, Here is a link to some pictures of a demo that efy-diy and I did at Bonneville in '08. I prepped the 270 in my '53 as instructed by Marc. GM coolant temp sensor, O2 sensor bung, electronic ignition, 12v hot,12v switched, good ground locations. and a fuel tank with return and supply lines. Marc brought his laptop, megasquirt, a TBI and wire harness from an '89 GM van. The TBI had the throttle position sensor and the IAC sensor on it. We hooked it up and had it running in a little less than an hour. We were not able to drive it because it blew the fuel line off twice, because of the temporary connection, and we had a vacuum leak under the TBI. A clean permanent set up will take a bit longer. It was getting late and I had to put the carb back on in the dark. I have now just finished putting my MS together and am in the process of putting it on my '68 that has a 350 in it for now. There are other posts here by guys who have used the GM ECMs. Beater Megasquirt

Thanks Beater. I'm going to stick with the stock 4.3L ECM and S-10 manual trans Harness. I'll make my 4L60 stand alone. I need to either get the lock-up removed or better still get another ECM for a manual trans S-10. I'm as giddy as a school kid at the thought of getting this thing together.

Randy S. Hager
Venus, TX

Randy, on the off chance you have a 4L60E (as opposed to a mechanical one) there is a controller by the name of Bauman.

I haven't used it, but I hear good things about it, and it's the cheapest I've seen without haveing to solder your own together (not that it's a bad thing ).

I don't work for, or sell any of these, but if you're interested.

http://www.becontrols.com/products/4L60Etcs.htm

Sounds like a neat project, keep us posted please.

I'm not sure what year S10 you're using but the TBI, harness and ECM from an '87-'92 full size will work. You may have to have a new prom burned. If you decide to go MSII later there is an adapter board that will make it plug into the GM harness. Look for GM ECM #1227747 & #122476. Beater

Well from my studies on these transmissions the 700R4 was only the first offerings in 82-89. After that they called them 4L60's until they went to full electronic controls then they became 4L60E. Wiki says they were renamed the 4L60 in 1990 (my trans). Yea I have read they still have kept the 700R4 name for a while too. Beater, I have a Astro van ECM right now but I do not remember the number. I bought a S-10 harness off eBay last year that was from a 4.3L 5 spd truck. Every thing is there except the lock-up wiring. I have been studying the blow thru TBI stuff on the net and will keep the GM ECM until I get the Brazilian head from Edy in Brazil for a Chevy II wagon build I want to do.

Randy S. Hager
Venus, TX

My 1991 Syclone has a 700R4,so did the 1992 Typhoon. All manual no electronics.Just had electronic lock-up for the converter.30 spline

I am pretty sure they call my trans a 700R4,@ least the Sy/Ty forums call them that.

4l60E's I think started in 1996 or so?

MBHD

Yea Hank Wiki says they started in 1992 and full in by 1996. Like I said they still use the 700R4 name up to the 1992-1996 electronic phase in. Yea and Wiki did say that the Sty/Ty trucks had the built (from factory) 700R4/4L60 trans. GM's official language after 1990 was 4L60 for non-electronic type O/D trans. WE still call them 700R4's.

Cool, I keep forgetting to use Wiki,most all my info I post are from the top of my head. LOL
My memory is still pretty good so far on the important stuff.

MBHD

Randy, it would be interesting to have your swap running at the inliners convention and then plug a MS into the harness to demo how to tune EFI. Right now I'm thinking of attending the convention in June.

In some reading somewhere it was said that the 4L60 had a lower first gear than the 700R4. Other wise they are the same. Mine is an '89. My memory is not as good as Hank's. Maybe because I don't have much on the top of my head. Beater

With going off the top of my head again LOL.
All 700R4 & 4L60, 4l60E's have 3:06 first gear.

There are aftermarket 1st & second gear sets that will give you a 2:75 forgot what second was.
Here is another set of different gear ratios.
1st 2.84 2nd,1.56 3rd 1 0.70
http://www.transmissionhead.com/

MBHD

I hate it when you're right.
700R4 " In 1990, the 700R4 was redesignated as the 4L60 (4-speeds, Longitudinally positioned, 6000 lbs. GVW). This was a change in name only with no significant mechanical changes associated."

Beater

It maybe a stretch to have it done by June. It will be then that I would have it in and running. I would like to be in San Antonio to meet in person some of you that I've had the privilege to converse with here on this board. BTW......I work 3rd shift so I will be answering sometime in the wee hours of the morning.

Randy S. Hager
Venus, TX

Yeah, I've got a '93 S-10 4X4 donor that I'm planning on putting the drivetrain into a '91 Geo Tracker (4.3 bent 6 and all) as a support (push) vehicle for Bonneville (easier to tow a 4X4 'cause you can put the T case in Neutral instead of unhooking the driveshaft).

It's got a 4L60E, it's the only reason I know anything about them (as opposed to the 700R4).

With the cost of the electronic controllers coming down, and the proliferation of the electronic trannies it's looking like pretty soon you will be able to retrofit the electronic version cheaper than the TV cable equipped stuff.

I figguer that's a good thing since a mis adjusted TV cable can destroy a 700R faster than anything I know (well, running it with no fluid might beat it, maybe).

This all may not be pertinent, but it's where I'm coming from.

Trasnsgo makes a vacumm modulator kit to allow a non-computer install of a 4l60E. It works well I used one before I got the megasquirt GPIO transmission controller working.

The vacumm modulator controls the line pressure.

The shift pattern can be controoled using 2 toggle switches. The convertor lockup can be controlled using a vacumm switch typically used oin GM TH350 lockup trans.

I've found the TransGo people to be very helpful on the phone.